Electric load simulator active-disturbance-rejection control high-frequency loading method introducing correction factor

Abstract

The invention relates to an active-disturbance-rejection control high-frequency loading method for an electric load simulator by introducing a correction factor. The invention relates to the technical field of motor control, and adopts a torque current double closed loop to control an electric load simulator, a current inner loop adopts PI control, and a torque outer loop adopts improved active disturbance rejection control. A third-order tracking differentiator is used for obtaining all-order differential signals of an instruction, an extended state observer is designed according to a mathematical model of the system to obtain internal and external disturbance of the system, and a second-order differential signal of the instruction and a correction factor lambda are introduced to improve a state error feedback control law. And performing frequency response analysis on the closed-loop system, and determining an appropriate value of the correction factor lambda. According to the invention, the loading precision of the electric load simulator meets the double-ten index while the redundant torque suppression effect is ensured, and the loading frequency of the electric load simulator is improved to 30Hz.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and is a high-frequency loading method for an electric load simulator with auto-disturbance rejection control introducing a correction factor. Background Art

[0002] Currently, electric load simulation systems have been widely used to simulate load torques for equipment such as aircraft actuators, robot joints, wind turbine generators, gun control systems, and vehicle transmission systems. The electric load simulator applies the required load torque to the device under test, which is called the loading system, and the device under test is called the bearing system. Due to the active movement of the bearing system, the electric load simulator needs to overcome the redundant torque brought by the active movement of the bearing system while following the loading torque command. Therefore, it is extremely difficult to achieve high-frequency and high-precision loading. The core idea of auto-disturbance rejection control (ADRC) is to use an integral cascade controller as the standard type and regard all unknown factors inside and outside the system as the total disturbance. An extended state observer is used to estimate and eliminate the total disturbance online, so as to achieve the feedback linearization of the dynamic system and simplify the design of the control system. Due to the anti-disturbance characteristics of auto-disturbance rejection control, this strategy has been used in electric load simulators to solve the problem of redundant torque.

[0003] Under the double-ten index, the loading frequency that the electric load simulator can meet usually does not exceed 20 Hz. When the loading frequency continues to increase, the amplitude attenuation and phase lag phenomena become more obvious, and the traditional PID control strategy and the existing auto-disturbance rejection control methods cannot meet the requirements of the double-ten index for the electric load simulator. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention improves the state error feedback control law in auto-disturbance rejection control. While ensuring the effect of suppressing redundant torque, the loading accuracy of the electric load simulator meets the double-ten index, and the loading frequency of the electric load simulator is increased to 30 Hz. The present invention provides a high-frequency loading method for an electric load simulator with auto-disturbance rejection control introducing a correction factor.

[0005] The present invention provides the following technical solutions:

[0006] A high-frequency loading method for an electric load simulator with auto-disturbance rejection control introducing a correction factor, the method comprising the following steps:

[0007] Step 1: Control the electric load simulator by using a double closed-loop of torque and current. The current inner loop uses PI control, and the torque outer loop uses improved auto-disturbance rejection control;

[0008] Step 2: Use a third-order tracking differentiator to obtain the differential signals of each order of the command. Design an extended state observer according to the system mathematical model to obtain the internal and external disturbances of the system. Introduce the second-order differential signal of the command and the correction factor λ to improve the state error feedback control law;

[0009] Step 3: Conduct a frequency response analysis on the closed-loop system to determine the appropriate value of the correction factor λ.

[0010] Preferably, the electric load simulator selects a permanent magnet synchronous motor as the loading motor and a servo system as the bearing system. The permanent magnet synchronous motor is rigidly connected to the servo through a torque sensor;

[0011] During the dynamic loading process, the servo actively moves according to the position command issued by the host computer. The permanent magnet synchronous motor follows the servo movement according to the loading command and applies a torque load to the servo at the same time.

[0012] Preferably, the specific content of Step 1 is as follows:

[0013] Simplify the mathematical model of the electric load simulation system. The permanent magnet synchronous motor adopts the i d =0 vector control strategy. After coordinate transformation and vector decoupling, the motor voltage equation is simplified as:

[0014]

[0015] Among them, u d , u q are the voltages of the direct and quadrature axes in the dq coordinate system; i d , i q are the currents of the direct and quadrature axes in the dq coordinate system; L and R are the motor inductance and resistance; ω e is the electrical angular velocity; ψ f is the permanent magnet flux linkage;

[0016] For the design of active disturbance rejection control, regard the current loop as an ideal link, and the motor mechanical motion equation is described as:

[0017]

[0018] Among them, ω is the mechanical angular velocity; J is the moment of inertia of the motor shaft; B is the damping coefficient; T L is the load torque;

[0019] The torque sensor is used to measure the load torque. According to Hooke's law, the load torque T L measured by the torque sensor is determined by the angular difference between the rotational mechanical angle θ of the loading motor and the active motion angle θ f of the servo system:

[0020] T L =T A Δθ = TA (θ - θ f )

[0021] Among them, T A —— torsional stiffness;

[0022] Obtain the transfer function model of the electric load simulation system:

[0023]

[0024] Preferably, the specific content of step 2 is as follows:

[0025] According to the requirements of the improved error feedback control law, use a third-order tracking differentiator as a transition process to obtain the tracking signal v1 of the command signal v and the differential signals v2 and v3 of each order:

[0026]

[0027] Among them, r is the fast factor. The larger r is, the faster the tracking speed is;

[0028] Convert according to the system transfer function model into a state-space equation:

[0029]

[0030] Regard the total system disturbance f as a new state variable and further deduce the state-space equation as:

[0031]

[0032]

[0033] Construct an extended state observer according to:

[0034]

[0035] Among them, z i is the estimated value of the state; β i is the observer gain; b0 is the control quantity gain;

[0036] Improve the traditional linear state error feedback control law. On the basis of the traditional PD controller, introduce the command second-order differential signal:

[0037]

[0038] Preferably, the specific content of step 3 is as follows:

[0039] Under the condition of ensuring system stability, introduce a correction factor λ to adjust the system zero point and further improve the system tracking performance. The improved state error feedback control law MSEF is expressed by the following formula:

[0040]

[0041] Let the controller output be \(u = u_0 - z_3 / b_0\), and the system is compensated to a series integral type standard structure. Derive the closed-loop transfer function of the system:

[0042]

[0043] Coefficients of the denominator of \(\varphi\):

[0044] \(A_0 = b_0\)

[0045] \(A_1 = b_0(p + \lambda k\) d + \(\beta_1)\)

[0046] \(A_2 = b_0(q + \beta_1\lambda k\) d + \(k\) p + \(\beta_2 + \beta_1p + \lambda k\) d \(p)\)

[0047] \(A_3 = b_0(\beta_1q + \lambda k\) d \(q + \beta_1\lambda k\) d \(p + k\) p \(p + \beta_2p) + b(k\) p \(\beta_1 + \lambda k\) d \(\beta_2 + \beta_3)\)

[0048] \(A_4 = b_0q(\lambda k\) d \(\beta_1 + k\) p + \(\beta_2) + b(k\) p \(\beta_2 + \lambda k\) d \(\beta_3)\)

[0049] \(A_5 = bk\) p \(\beta_3\)

[0050] Coefficients of the numerator of \(\varphi\):

[0051] \(B_0 = b\)

[0052] \(B_1 = b(\lambda k\) d + \(\beta_1)\)

[0053] \(B_2 = b(k\) p + \(\lambda k\) d \(\beta_1 + \beta_2)\)

[0054] \(B_3 = b(k\) p \(\beta_1 + \lambda k\) d \(\beta_2 + \beta_3)\)

[0055] \(B_4 = b(\lambda k\) d \(\beta_3 + k\) p \(\beta_2)\)

[0056] \(B_5 = bk\) p \(\beta_3\)

[0057]

[0058] Draw the system frequency response curves with different values of the correction factor λ. Under the condition of meeting the double-ten index, determine the value of λ according to the highest loading frequency supported by the system.

[0059] Preferably, perform gradient loading on the load simulator to verify the redundant torque suppression performance and the instruction signal tracking accuracy.

[0060] Preferably, when the loading frequency is increased to 30 Hz, the tracking accuracy of the system for torque commands meets the requirements of the double-ten index.

[0061] An active disturbance rejection control high-frequency loading system for an electric load simulator with a correction factor introduced, the system comprising:

[0062] A control module that controls the electric load simulator by using a double closed-loop of torque and current. The current inner loop uses PI control, and the torque outer loop uses an improved active disturbance rejection control;

[0063] A differential module that uses a third-order tracking differentiator to obtain the differential signals of each order of the command, designs an extended state observer to obtain the internal and external disturbances of the system according to the system mathematical model, and improves the state error feedback control law by introducing the second-order differential signal of the command and the correction factor λ;

[0064] A correction factor determination module that performs frequency response analysis on the closed-loop system to determine the appropriate value of the correction factor λ.

[0065] A computer-readable storage medium, on which a computer program is stored, and the program is executed by a processor to implement an active disturbance rejection control high-frequency loading method for an electric load simulator with a correction factor introduced.

[0066] A computer device, including a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, it implements an active disturbance rejection control high-frequency loading method for an electric load simulator with a correction factor introduced.

[0067] The present invention has the following beneficial effects:

[0068] The present invention proposes a high-frequency loading method for an electric load simulator with an auto-disturbance rejection control (ADRC) that introduces a correction factor. The electric load simulator selects a permanent magnet synchronous motor as the loading motor and a servo system as the bearing system. The permanent magnet synchronous motor is rigidly connected to the servo through a torque sensor. During the dynamic loading process, the servo actively moves according to the position command issued by the upper computer, and the permanent magnet synchronous motor applies a torque load to the servo while following the movement of the servo according to the loading command. Since the movement of the servo is independent, the loading system will inevitably be affected by the strong interference caused by the active movement of the servo system during the process of tracking the desired torque input command. Considering the requirements of high-frequency loading for the outer loop bandwidth of the controller, the three-loop structure is not applicable to the electric load simulator. Therefore, a double closed-loop of torque and current is used to control the electric load simulator. The current inner loop uses PI control, and the torque outer loop uses an improved auto-disturbance rejection control. The improved auto-disturbance rejection control strategy includes links such as a tracking differentiator (TD), an extended state observer (ESO), and an improved state error feedback control law (MSEF). The third-order tracking differentiator is used to obtain the differential signals of each order of the command. The extended state observer is designed according to the system mathematical model to obtain the internal and external disturbances of the system. The state error feedback control law is improved by introducing the second-order differential signal of the command and the correction factor λ. The frequency response analysis of the closed-loop system is carried out to determine the appropriate value of the correction factor λ.

[0069] Compared with the existing methods, the present invention proposes a high-frequency loading method for an electric load simulator with an auto-disturbance rejection control that introduces a correction factor. By improving the state error feedback control law in the auto-disturbance rejection control, the parameter tuning is simple. While ensuring the effect of suppressing the surplus torque, the loading accuracy of the electric load simulator meets the double-ten index, and the loading frequency of the electric load simulator is increased to 30 Hz. Brief Description of the Drawings

[0070] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0071] Figure 1 It shows a schematic diagram of the structure of the electric load simulation system of the present invention;

[0072] Figure 2 It shows a schematic diagram of the control principle of the loading system of the present invention;

[0073] Figure 3 It shows a simplified mathematical model of the electric load simulation system of the present invention;

[0074] Figure 4 Shown is the control block diagram of the loading system of the present invention;

[0075] Figure 5 Shown are the frequency response curves of the electric simulation system under the action of different reference factors λ;

[0076] Figure 6 Shown is the surplus torque generated by the system when the servo motion command is a sine signal with a frequency of 30 Hz and an amplitude of 1° and the torque command is zero;

[0077] Figure 7 Shown is the tracking curve of the system for the torque command when the servo motion command is a sine signal with a frequency of 30 Hz and an amplitude of 1° and a gradient loading is performed at 300 Nm / °. Detailed implementation manners

[0078] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0079] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0080] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0081] The present invention is described in detail below in conjunction with specific embodiments. Specific Embodiment 1:

[0083] According to Figures 1 to 7As shown in the figure, the specific optimized technical solution adopted by the present invention to solve the above technical problems is: The present invention relates to a high-frequency loading method for an electric load simulator with auto-disturbance rejection control introduced with a correction factor.

[0084] The present invention provides a high-frequency loading method for an electric load simulator with auto-disturbance rejection control introduced with a correction factor, and the method includes the following steps:

[0085] Step 1: Use a torque-current double closed-loop to control the electric load simulator. The current inner loop uses PI control, and the torque outer loop uses improved auto-disturbance rejection control;

[0086] Step 2: Use a third-order tracking differentiator to obtain the differential signals of each order of the command. Design an extended state observer according to the system mathematical model to obtain the internal and external disturbances of the system. Introduce the second-order differential signal of the command and the correction factor λ to improve the state error feedback control law;

[0087] Step 3: Conduct a frequency response analysis on the closed-loop system to determine the appropriate value of the correction factor λ.

[0088] The present invention provides a high-frequency loading method for an electric load simulator with auto-disturbance rejection control (ADRC) introduced with a correction factor. The electric load simulator selects a permanent magnet synchronous motor as the loading motor and a servo system as the bearing system. The permanent magnet synchronous motor is rigidly connected to the servo through a torque sensor. During the dynamic loading process, the servo actively moves according to the position command issued by the upper computer. The permanent magnet synchronous motor follows the movement of the servo while applying a torque load to the servo according to the loading command. Since the movement of the servo is independent, the loading system will inevitably be affected by the strong interference caused by the active movement of the servo system during the process of tracking the desired torque input command. Considering the requirements of high-frequency loading for the outer loop bandwidth of the controller, the three-loop structure is not applicable to the electric load simulator. Therefore, a torque-current double closed-loop is used to control the electric load simulator. The current inner loop uses PI control, and the torque outer loop uses improved auto-disturbance rejection control. The improved auto-disturbance rejection control strategy includes links such as a tracking differentiator (TD), an extended state observer (ESO), and an improved state error feedback control law (MSEF). Use a third-order tracking differentiator to obtain the differential signals of each order of the command. Design an extended state observer according to the system mathematical model to obtain the internal and external disturbances of the system. Introduce the second-order differential signal of the command and the correction factor λ to improve the state error feedback control law. Conduct a frequency response analysis on the closed-loop system to determine the appropriate value of the correction factor λ. Specific Embodiment 2:

[0090] The difference between the second embodiment of this application and the first embodiment is only that:

[0091] The electric load simulator selects a permanent magnet synchronous motor as the loading motor and a servo system as the bearing system. The permanent magnet synchronous motor is rigidly connected to the servo through a torque sensor;

[0092] During the dynamic loading process, the servo moves actively according to the position command issued by the host computer. The permanent magnet synchronous motor loads torque on the servo while following the movement of the servo according to the loading command. Specific Embodiment Three:

[0094] The difference between Embodiment Three and Embodiment Two of this application is only that:

[0095] The specific content of Step 1 is:

[0096] Simplify the mathematical model of the electric load simulation system. The permanent magnet synchronous motor adopts the i d = 0 vector control strategy. After coordinate transformation and vector decoupling, the motor voltage equation is simplified to:

[0097]

[0098] Among them, u d , u q are the voltages of the direct and quadrature axes in the dq coordinate system; i d , i q are the currents of the direct and quadrature axes in the dq coordinate system; L and R are the motor inductance and resistance; ω e is the electrical angular velocity; ψ f is the permanent magnet flux linkage;

[0099] For the design of active disturbance rejection control, regarding the current loop as an ideal link, the motor mechanical motion equation is described as:

[0100]

[0101] Among them, ω is the mechanical angular velocity; J is the moment of inertia of the motor shaft; B is the damping coefficient; T L is the load torque;

[0102] The torque sensor is used to measure the load torque. According to Hooke's law, the load torque T L measured by the torque sensor is determined by the angular difference between the rotational mechanical angle θ of the loading motor and the active motion angle θ f of the servo system:

[0103] T L = T A Δθ = T A (θ - θ f )

[0104] Among them, T A —— torsional stiffness;

[0105] Obtain the transfer function model of the electric load simulation system:

[0106] Specific Embodiment Four:

[0108] The difference between Embodiment Four and Embodiment Three of this application lies only in:

[0109] The specific content of step 2 is:

[0110] According to the requirements of the improved error feedback control law, use a third-order tracking differentiator as a transition process to obtain the tracking signal v1 of the command signal v and the differential signals v2, v3 of each order:

[0111]

[0112] where r is the fast factor, and the larger r is, the faster the tracking speed;

[0113] Convert according to the system transfer function model into a state-space equation:

[0114]

[0115] Regard the total disturbance f of the system as a new state variable, and the state-space equation is further derived as:

[0116]

[0117] Construct an extended state observer according to:

[0118]

[0119] where z i is the estimated value of the state; β i is the observer gain; b0 is the control quantity gain;

[0120] Improve the traditional linear state error feedback control law. On the basis of the traditional PD controller, introduce the command second-order differential signal:

[0121] Specific Embodiment Five:

[0123] The difference between Embodiment Five and Embodiment Four of this invention lies only in:

[0124] The specific content of step 3 is:

[0125] Under the condition of ensuring system stability, introduce a correction factor λ to adjust the system zero point and further improve the system tracking performance. The improved state error feedback control law MSEF is expressed by the following formula:

[0126]

[0127] Let the controller output be \(u = u_0 - z_3 / b_0\), and the system is compensated to a series-integral type standard structure. Derive the closed-loop transfer function of the system:

[0128]

[0129] Coefficients of the denominator of \(\varphi\):

[0130] \(A_0 = b_0\)

[0131] \(A_1 = b_0(p+\lambda k\) d +\(\beta_1)\)

[0132] \(A_2 = b_0(q+\beta_1\lambda k\) d +k p +\(\beta_2+\beta_1p+\lambda k\) d p)

[0133] \(A_3 = b_0(\beta_1q+\lambda k\) d q+\(\beta_1\lambda k\) d p+k p p+\(\beta_2p)+b(k\) p \(\beta_1+\lambda k\) d \(\beta_2+\beta_3)\)

[0134] \(A_4 = b_0q(\lambda k\) d \(\beta_1+k\) p +\(\beta_2)+b(k\) p \(\beta_2+\lambda k\) d \(\beta_3)\)

[0135] \(A_5 = bk\) p \(\beta_3\)

[0136] Coefficients of the numerator of \(\varphi\):

[0137] \(B_0 = b\)

[0138] \(B_1 = b(\lambda k\) d +\(\beta_1)\)

[0139] \(B_2 = b(k\) p +\(\lambda k\) d \(\beta_1+\beta_2)\)

[0140] \(B_3 = b(k\) p \(\beta_1+\lambda k\) d \(\beta_2+\beta_3)\)

[0141] \(B_4 = b(\lambda k\) d \(\beta_3+k\) p \(\beta_2)\)

[0142] \(B_5 = bk\) p \(\beta_3\)

[0143]

[0144] Draw the system frequency response curves with different values of the correction factor λ, and determine the value of λ according to the highest loading frequency supported by the system under the condition of meeting the double-ten index. Specific Embodiment Six:

[0146] The difference between Embodiment Six and Embodiment Five of the present invention lies only in:

[0147] Perform gradient loading on the load simulator to verify the redundant torque suppression performance and the instruction signal tracking accuracy. Specific Embodiment Seven:

[0149] The difference between Embodiment Seven and Embodiment Six of the present invention lies only in:

[0150] When the loading frequency is increased to 30 Hz, the tracking accuracy of the system for torque commands meets the requirements of the double-ten index. Specific Embodiment Eight:

[0152] The difference between Embodiment Eight and Embodiment Seven of the present invention lies only in:

[0153] The present invention provides an active disturbance rejection control high-frequency loading system for an electric load simulator introducing a correction factor, and the system includes:

[0154] A control module, which controls the electric load simulator by using a double closed-loop of torque and current. The current inner loop adopts PI control, and the torque outer loop adopts an improved active disturbance rejection control;

[0155] A differential module, which uses a third-order tracking differentiator to obtain the differential signals of each order of the instruction, designs an extended state observer according to the system mathematical model to obtain the internal and external disturbances of the system, and improves the state error feedback control law by introducing the second-order differential signal of the instruction and the correction factor λ;

[0156] A correction factor determination module, which performs frequency response analysis on the closed-loop system to determine the appropriate value of the correction factor λ.

[0157] The present invention proposes a high-frequency loading method for an electric load simulator with an auto-disturbances rejection control (ADRC) introducing a correction factor. The electric load simulator selects a permanent magnet synchronous motor as the loading motor and a servo system as the bearing system. The permanent magnet synchronous motor is rigidly connected to the servo through a torque sensor. During the dynamic loading process, the servo actively moves according to the position command issued by the host computer, and the permanent magnet synchronous motor applies torque loading to the servo while following the movement of the servo according to the loading command. Since the movement of the servo is independent, the loading system will inevitably be affected by the strong interference caused by the active movement of the servo system during the process of tracking the desired torque input command. Considering the requirements of high-frequency loading for the outer-loop bandwidth of the controller, the three-loop structure is not applicable to the electric load simulator. Therefore, a torque-current double closed-loop is used to control the electric load simulator. The current inner loop uses PI control, and the torque outer loop uses an improved auto-disturbances rejection control. The improved auto-disturbances rejection control strategy includes links such as a tracking differentiator (TD), an extended state observer (ESO), and an improved state error feedback control law (MSEF). The third-order tracking differentiator is used to obtain the differential signals of each order of the command, and the extended state observer is designed according to the system mathematical model to obtain the internal and external disturbances of the system. The state error feedback control law is improved by introducing the second-order differential signal of the command and the correction factor λ. The frequency response analysis of the closed-loop system is carried out to determine the appropriate value of the correction factor λ.

[0158] Compared with the existing methods, the present invention proposes a high-frequency loading method for an electric load simulator with an auto-disturbances rejection control introducing a correction factor. By improving the state error feedback control law in the auto-disturbances rejection control, the parameter tuning is simple. While ensuring the effect of suppressing the surplus torque, the loading accuracy of the electric load simulator meets the double-ten index, and the loading frequency of the electric load simulator is increased to 30 Hz. Specific Embodiment Nine:

[0160] The difference between the ninth embodiment and the eighth embodiment of the present invention is only that:

[0161] The present invention provides a computer-readable storage medium, on which a computer program is stored, and the program is executed by a processor to implement a high-frequency loading method for an electric load simulator with an auto-disturbances rejection control introducing a correction factor. Specific Embodiment Ten:

[0163] The difference between the tenth embodiment and the ninth embodiment of the present invention is only that:

[0164] The present invention provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements a high-frequency loading method for an electric load simulator with an auto-disturbances rejection control introducing a correction factor. Specific Embodiment Eleven:

[0166] The difference between the eleventh embodiment and the tenth embodiment of the present invention lies only in that:

[0167] Figure 1 As shown in the structural schematic diagram of the electric load simulation system of the present invention, the electric load simulator selects a permanent magnet synchronous motor as the loading motor and a servo system as the bearing system. The permanent magnet synchronous motor is rigidly connected to the servo through a torque sensor. During the dynamic loading process, the servo actively moves according to the position command issued by the upper computer, and the permanent magnet synchronous motor applies a torque load to the servo while following the movement of the servo according to the loading command. Since the movement of the servo is independent, the loading system will inevitably be affected by the strong interference caused by the active movement of the servo system during the process of tracking the desired torque input command.

[0168] Figure 2 As shown in the system control schematic diagram, considering the requirements of high-frequency loading for the outer-loop bandwidth of the controller, the three-loop structure is not applicable to the electric load simulator. Therefore, a torque-current double closed-loop is used to control the electric load simulator. The current inner loop uses PI control, and the torque outer loop uses an improved active disturbance rejection control. The improved active disturbance rejection control strategy includes links such as a tracking differentiator (TD), an extended state observer (ESO), and an improved state error feedback control law (MSEF). A third-order tracking differentiator is used to obtain the differential signals of each order of the command, and an extended state observer is designed according to the system mathematical model to obtain the internal and external disturbances of the system. The state error feedback control law is improved by introducing the second-order differential signal of the command and the correction factor λ. The frequency response analysis of the closed-loop system is carried out to determine the appropriate value of the correction factor λ.

[0169] Figure 3 As shown in the simplified mathematical model of the electric load simulation system. The permanent magnet synchronous motor adopts the i d = 0 vector control strategy. After coordinate transformation and vector decoupling, the motor voltage equation can be simplified as:

[0170]

[0171] In the formula, u d , u q ——Voltages on the direct and quadrature axes in the dq coordinate system (V);

[0172] i d , i q ——Currents on the direct and quadrature axes in the dq coordinate system (A);

[0173] L, R——Motor inductance (H), resistance (Ω);

[0174] ω e ——Electrical angular velocity (rad);

[0175] ψ f—— Permanent magnet flux linkage (Wb).

[0176] Since the servo driver integrates the current loop algorithm and the bandwidth of the current loop is much higher than that of the outer loop, the response speed of the electromagnetic torque loaded on the motor is much higher than that of the motor load torque, and the lag of the electromagnetic torque response can be ignored. For the convenience of the design of the active disturbance rejection control, the current loop can be regarded as an ideal link.

[0177] The mechanical motion equation of the motor can be described as:

[0178]

[0179] where ω —— Mechanical angular velocity (rad);

[0180] J —— Moment of inertia of the motor shaft (kg·m 2 );

[0181] B —— Damping coefficient (Nm / rad / s);

[0182] T L —— Load torque (Nm).

[0183] The torque sensor is used to measure the load torque. Ignoring the influence of its own inertia and the torque transmission process on the loading system, the torque sensor can be approximated as an elastic model. According to Hooke's law, the load torque T measured by the torque sensor L is determined by the angular difference between the rotational mechanical angle θ of the loading motor and the active motion angle θ f of the servo system.

[0184] T L = T A Δθ = T A (θ - θ f )

[0185] where T A —— Torsional stiffness;

[0186] The transfer function model of the electric load simulation system is obtained:

[0187]

[0188] The electric load system belongs to a double-input single-output system. The active motion of the servo system is presented in the form of an external disturbance θ f . Therefore, the servo motion will inevitably generate a disturbing torque at the torque output end. This disturbing torque is the redundant torque, which affects the system tracking accuracy and must be suppressed and compensated. Therefore, the active disturbance rejection control strategy is adopted in the torque outer loop.

[0189] According to the requirements of the improved error feedback control law, a third-order tracking differentiator is used as the transition process to obtain the tracking signal v1 of the command signal v and the differential signals v2 and v3 of each order:

[0190]

[0191] where r is the fast factor. The larger r is, the faster the tracking speed is.

[0192] According to the system transfer function model, it can be converted into a state-space equation:

[0193]

[0194] where

[0195]

[0196] Regarding the total system disturbance f as the expanded new state variable, the state-space equation is further derived as:

[0197]

[0198] where

[0199]

[0200] According to this, an extended state observer is constructed:

[0201]

[0202] where z i —— the estimated value of the state;

[0203] β i —— the observer gain;

[0204] b0 is the control quantity gain.

[0205] Improve the traditional linear state error feedback control law. On the basis of the traditional PD controller, introduce the second-order differential signal of the command:

[0206]

[0207] While ensuring the stability of the system, introduce a correction factor λ to adjust the system zero point and further improve the system tracking performance. The improved state error feedback control law (MSEF) can be written as:

[0208]

[0209] Let the controller output u = u0 - z3 / b0, and the system is compensated to a series integral type standard structure, and the system closed-loop transfer function is derived:

[0210]

[0211] φ denominator coefficient:

[0212] A0 = b0

[0213] A1 = b0(p + λk d + β1)

[0214] A2 = b0(q + β1λk d + k p + β2 + β1p + λk d p)

[0215] A3 = b0(β1q + λk d q + β1λk d p + k p p + β2p) + b(k p β1 + λk d β2 + β3)

[0216] A4 = b0q(λk d β1 + k p + β2) + b(k p β2 + λk d β3)

[0217] A5 = bk p β3

[0218] φ numerator coefficient:

[0219] B0 = b

[0220] B1 = b(λk d + β1)

[0221] B2 = b(k p + λk d β1 + β2)

[0222] B3 = b(k p β1 + λk d β2 + β3)

[0223] B4 = b(λk d β3 + k p β2)

[0224] B5 = bk p β3

[0225] Where:

[0226]

[0227] Plot the system frequency response curves with different values of the drawing correction factor λ. Under the condition of meeting the double-ten index, determine the value of λ according to the highest loading frequency supported by the system.

[0228] According to the technical requirements, perform gradient loading on the load simulator to verify the redundant torque suppression performance and the instruction signal tracking accuracy.

[0229] Figure 5 It is the frequency response curve of the electric simulation system under the action of different reference factors λ.

[0230] Figure 6 It is the redundant torque generated by the system when the servo motion instruction is a sine signal with a frequency of 30 Hz and an amplitude of 1° and the torque instruction is zero.

[0231] Figure 7 It is the tracking curve of the system for the torque instruction when the servo motion instruction is a sine signal with a frequency of 30 Hz and an amplitude of 1° and gradient loading is performed at 300 Nm / °.

[0232] It can be seen from the above simulation curves that the present invention is an active disturbance rejection control high-frequency loading method for an electric load simulator introducing a correction factor. When the loading frequency is increased to 30 Hz, the tracking accuracy of the system for the torque instruction meets the requirements of the double-ten index.

[0233] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Furthermore, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "N" is at least two, such as two, three, etc., unless otherwise specifically defined. Any process or method description represented in a flowchart or described in other ways herein can be understood to represent a module, segment, or portion of code including one or more N executable instructions for implementing a customized logical function or process, and the scope of the preferred embodiments of the present invention includes additional implementations, where the functions can be executed in a substantially simultaneous manner or in a reverse order according to the involved functions, rather than in the order shown or discussed, which should be understood by those skilled in the art to which the embodiments of the present invention belong. The logic and / or steps represented in a flowchart or described in other ways herein, for example, can be considered as a sequenced list of executable instructions for implementing a logical function, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in combination with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion (electronic device) having one or N wirings, a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM).In addition, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation or, if necessary, other suitable processing, and then stored in a computer memory. It should be understood that various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiments, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits with logic gate circuits for implementing logical functions on data signals, application specific integrated circuits with suitable combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0234] The above is only a preferred embodiment of the active load simulator auto-disturbance rejection control high-frequency loading method introducing a correction factor. The protection scope of the active load simulator auto-disturbance rejection control high-frequency loading method introducing a correction factor is not limited to the above embodiments. Any technical solutions falling within this concept belong to the protection scope of the present invention. It should be noted that for those skilled in the art, several improvements and changes made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A high-frequency loading method for an active load simulator with auto-disturbance rejection control introducing a correction factor, characterized in that: The method includes the following steps: Step 1: Use a double closed-loop of torque and current to control the electric load simulator. The current inner loop uses PI control, and the torque outer loop uses an improved active disturbance rejection control; Step 2: Use a third-order tracking differentiator to obtain the differential signals of each order of the command. Design an extended state observer according to the system mathematical model to obtain the internal and external disturbances of the system. Introduce the second-order differential signal of the command and the correction factor λ to improve the state error feedback control law; Step 3: Conduct a frequency response analysis on the closed-loop system to determine the appropriate value of the correction factor λ.

2. The method according to claim 1, wherein: The electric load simulator selects a permanent magnet synchronous motor as the loading motor and a servo system as the bearing system. The permanent magnet synchronous motor is rigidly connected to the servo through a torque sensor; During the dynamic loading process, the servo actively moves according to the position command issued by the upper computer. The permanent magnet synchronous motor follows the movement of the servo and applies a torque load to the servo according to the loading command.

3. The method according to claim 2, characterized in that: The specific content of step 1 is as follows: Simplify the mathematical model of the electric load simulation system. For the permanent magnet synchronous motor, the i d = 0 vector control strategy is adopted. After coordinate transformation and vector decoupling, the motor voltage equation is simplified to: where u d , u q are the direct-axis and quadrature-axis voltages in the dq coordinate system; i d , i q are the direct-axis and quadrature-axis currents in the dq coordinate system; L and R are the motor inductance and resistance; ω e is the electrical angular velocity; ψ f is the permanent magnet flux linkage; For the design of the active disturbance rejection control, regard the current loop as an ideal link, and the motor mechanical motion equation is described as: where ω is the mechanical angular velocity; J is the moment of inertia of the motor shaft; B is the damping coefficient; T L is the load torque; The torque sensor is used to measure the load torque. According to Hooke's law, the load torque T measured by the torque sensor L is determined by the angular difference between the rotational mechanical angle θ of the loading motor and the active movement angle θ of the servo system f : T L = T A Δθ = T A (θ - θ f ) where T A —— torsional stiffness; Obtain the transfer function model of the electric load simulation system:

4. The method according to claim 3, characterized in that: The specific content of step 2 is as follows: According to the requirements of the improved error feedback control law, use a third-order tracking differentiator as a transition process to obtain the tracking signal v1 of the command signal v and the differential signals v2, v3 of each order: Where r is the fast factor, and the larger r is, the faster the tracking speed; Convert the system transfer function model into a state space equation: Regard the total disturbance f of the system as a new state variable for expansion, and further deduce the state space equation: Construct an extended state observer according to: where z i is the estimated value of the state; β i is the observer gain; b0 is the control quantity gain; Improve the traditional linear state error feedback control law. On the basis of the traditional PD controller, introduce the second-order differential signal of the command:

5. The method according to claim 4, characterized in that: The specific content of step 3 is as follows: Under the condition of ensuring system stability, introduce the correction factor λ to adjust the system zero point and further improve the system tracking performance. The improved state error feedback control law MSEF is expressed by the following formula: Let the controller output u = u0 - z3 / b0, and the system is compensated to a series integral type standard structure, and deduce the system closed-loop transfer function: Denominator coefficient of φ: A0 = b0 A1 = b0(p + λk d + β1) A2 = b0(q + β1λk d + k p + β2 + β1p + λk d p) A3 = b0(β1q + λk d q + β1λk d p + k p p + β2p) + b(k p β1 + λk d β2 + β3) A4 = b0q(λk d β1 + k p + β2) + b(k p β2 + λk d β3) A5 = bk p β3 Numerator coefficient of φ: B0 = b B1 = b(λk d + β1) B2 = b(k p + λk d β1 + β2) B3 = b(k p β1 + λk d β2 + β3) B4 = b(λk d β3 + k p β2) B5 = bk p β3 Draw the system frequency response curves when the correction factor λ takes different values. Under the condition of meeting the double-ten index, determine the value of λ according to the highest loading frequency supported by the system.

6. The method according to claim 5, wherein: Perform gradient loading on the load simulator to verify the performance of suppressing the surplus torque and the tracking accuracy of the command signal.

7. The method according to claim 6, wherein: When the loading frequency is increased to 30Hz, the tracking accuracy of the system for the torque command meets the requirements of the double-ten index.

8. An active load simulator auto-disturbance rejection control high-frequency loading system introducing a correction factor, characterized in that: The system includes: A control module, which uses a double closed-loop of torque and current to control the electric load simulator. The current inner loop uses PI control, and the torque outer loop uses an improved active disturbance rejection control; Differential module, which uses a third-order tracking differentiator to obtain differential signals of each order of the instruction, designs an extended state observer according to the system mathematical model to obtain internal and external disturbances of the system, and improves the state error feedback control law by introducing the second-order differential signal of the instruction and the correction factor λ; Correction factor determination module, which conducts frequency response analysis on the closed-loop system to determine the appropriate value of the correction factor λ.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, This program is executed by a processor to implement the method according to claims 1-7.

10. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that: When the processor executes the computer program, it implements the method according to claims 1-7.

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